Ad-hoc communications networks, otherwise known as mesh networks are known in the state of the art. A wireless mesh network is a communications network comprising a number of wireless receivers, known as nodes, organised in a mesh topology, wherein each of the receivers is also capable of wirelessly transmitting a received signal to one or more of the other nodes in the network. On the other hand, a standard cellular network requires a backbone network connecting cell base stations, wherein the communication must take place over the backbone. A mesh network has the advantage in that it is fully self-configurable and self-healing. After distributing the nodes over a widespread area the nodes themselves discover their nearest neighbours, and discover routes to other nodes in the network independently. Thus, a signal destined to be sent from a point A to a point B may be routed via intermediate nodes in the thus-established mesh network from point A until it reaches point B. If one of the nodes in the network fails, then the network can automatically reconfigure, or “heal”, itself to compensate by finding an alternative route from A to B via another combination of intermediate nodes between A and B. This redundancy is made possible by the fact that nodes not affected by an outage are capable of finding each other and setting up new links between themselves, thereby ensuring that a message can still be correctly transmitted in spite of the outage caused by the failure of one or more nodes within the network.
Mesh-networks are perfect for networking large, sparsely inhabited regions or regions which have no existing communications network or where the existing communications network is otherwise damaged or where there is a need to establish a new network as an alternative to an existing network. Such mesh networks tend to rely on batteries, thereby limiting their usefulness over time.
The process of deploying wireless mesh networks is also of concern within the scope of the present invention. Parachutes are known in the state of the art for deploying payloads to remote areas. They are generally circular or conical in design and, once deployed, descend almost vertically through the air where prevailing winds or local air currents may further influence their descent, thus leading to uncertainty as to their eventual particular landing positions. This presents a disadvantage when the payload is to be recovered for example, requiring that the payload land in a spot which is accessible to personnel on the ground. A further disadvantage is that a parachute may have a rate of descent anywhere in the order of around 5 to 10 meters per second (18 km/h to 36 km/h approx.) or possibly even more, depending on the weight of the parachute's payload and the shape and dimensions of the parachute. (Equations allowing for the calculation of speed of descent of a parachute through air depending on the weight of the payload and the form and dimension of the parachute are readily available in the state of the art). This (speed at landing) may lead to damage of the payload when it lands on solid or otherwise rough ground and especially when the payload is fragile. Such problems may be alleviated by releasing the parachute with its payload above a body of water but presents the disadvantage in that the payload then requires to be protected from the water, thus leading to further complexities such as the need for flotation devices and the need to have payloads of a type which cannot be damaged by water.
U.S. Pat. No. 6,416,019 B1 offers a solution to some of the problems mentioned above, by providing a ram-air inflated parachute, otherwise known as a parafoil or parasail, which has the advantage that it is steerable. This allows for the payload to be deployed accurately at a predetermined target and provides a further advantage in that by appropriately guiding the parasail, its speed of descent may be slowed down or otherwise regulated, especially during landing, when the parasail may be guided so as to face the wind thereby providing a soft (slow) landing. A disadvantage of the state of the art parafoil however, is that it requires a human pilot to steer it. According to the mentioned Publication, a parasail system is provided for deploying a payload, the system comprising a parasail having a rectangular shape, and further comprising a guidance control electronics and servo system to control the glide trajectory of the parasail system with respect to a predetermined trajectory.
United States Patent Application Publication number 2013/0,009,014 A1 also discloses a parafoil and payload assembly to guide a deployed payload towards a predetermined target position according to a predetermined glide path. According to a particular embodiment of the invention disclosed therein, the payload comprises a control unit having wireless interface communications circuitry. Such communications circuitry may be useful for example for uploading ground wind magnitude following deployment and during the decent of the parafoil with its payload, or uploading a continuously moving target position during decent. The control unit may be configured to transmit any of all of its measurement information to a control center via the communications circuitry. Furthermore, one control unit may be able to communicate wind speed information for example during its decent to another control unit above it. In this way, a group of descending control units may establish a temporary wireless network during their decent. This may be interpreted as being an ad-hoc or mesh network, especially when the control units further comprise wireless network routing and/or switching software/hardware to route packets, thereby allowing a packet sent from an access point to reach a remote location by way of relaying via nodal hops from control unit to control unit until the packet reaches the remote location (or vice versa from the remote location to the access point). According to another particular embodiment described in the mentioned application, such an ad-hoc network may continue to function long after the control units have landed. Nearest neighbour awareness technology comprised within the control units allow for the control units to configure the mesh network automatically.